The present disclosure relates generally to drug delivery technology including injection devices that are modified to be more easily used. Such devices include manual syringes, autoinjectors, and related fluid delivery apparatuses. Various structures, methods of making, and methods of using such injection devices are also disclosed.
Several drugs, vaccines, medications, therapeutic agents, diagnostic agents, etc. are administered via injection devices such as manual syringes and auto-injectors. This preferably occurs under sterile conditions. Generally, such devices include a barrel or tube containing a formulation, and a piston (such as a rubber piston) for ejecting the formulation in the barrel through a hollow injection needle. The needle pierces the skin into the body and delivers the substance by various routes such as intravenously, intramuscularly, subcutaneously, etc. The motive force for ejecting the formulation can be manual (e.g. pushing the thumb down on the device) or mechanical (e.g. a spring, a battery, etc.). The piston is pushed along the inside of the barrel, allowing the fluid (liquid or gas) to be expelled through an orifice at the end of the tube fitted with a needle, such as a hypodermic needle. Several medications are commonly self-administered by laypersons, for example in the administration of insulin by diabetics. Such self-administration reduces costs, increases convenience to the patient, and increases patient compliance.
Current syringe and auto-injector form factors and ergonomics are designed for a general patient population. For example, the user interfaces and control surfaces, such as the fingerflange on the barrel and the thumbrest on the plunger, are rather small. The plunger of a syringe is also vertically oriented. While suitable for a large majority, these traditional designs present challenges in handling and operation to a minority of patients, and may lead to use errors that become barriers to effective self-injection treatments. In particular, patients with finger/hand deformities or with reduced strength, dexterity, or coordination can find traditional syringes and auto-injectors difficult to use. These symptoms and conditions are common in people with rheumatoid arthritis (RA), multiple sclerosis (MS), who may otherwise be able to self-administer such medications.